成都市农村生活垃圾分类收运处理进展及模式研究

介绍了成都市农村生活垃圾分类试点工作的进展情况,通过调研和总结试点工作经验,归纳出一种适应成都市农村的生活垃圾分类收运处理模式,并从政策法规、制度激励、设施建设、宣传培训和技术研发等方面提出了建议。     

A homozygous mutation in the NDUFS1 gene presents with a mild cavitating leukoencephalopathy

We report a case of mild cavitating leukoencephalopathy associated with a homozygous c.755A > G (p.Asp252Gly) NDUFS1 mutation in a 7-year old boy. Biochemical analysis confirmed an isolated reduction in complex I activity. Magnetic resonance imaging of the brain showed a diffuse cystic leukoencephalopathy with the involvement of the corpus callosum and sparing of the gray matter. The clinical course was marked by an acute presentation of neurological deficits at 24 months followed by recurrent episodes of mild neurological deterioration, subsequent remissions, and prolonged periods of stability. This is one of the mildest known clinical presentations of complex I deficiency secondary to mutations in NDUFS1, expanding the clinical spectrum and natural history of this disorder. Consideration of clinical variability needs to be taken into account in patient management and family counseling.     

SARS-CoV-2 spike protein favors ACE2 from Bovidae and Cricetidae

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes the recent COVID-19 public health crisis. Bat is the widely believed original host of SARS-CoV-2. However, its intermediate host before transmitting to humans is not clear. Some studies proposed pangolin, snake, or turtle as the intermediate hosts. Angiotensin-converting enzyme 2 (ACE2) is the receptor for SARS-CoV-2, which determines the potential host range for SARS-CoV-2. On the basis of structural information of the complex of human ACE2 and SARS-CoV-2 receptor-binding domain (RBD), we analyzed the affinity to S protein of the 20 key residues in ACE2 from mammal, bird, turtle, and snake. Several ACE2 proteins from Primates, Bovidae, Cricetidae, and Cetacea maintained the majority of key residues in ACE2 for associating with SARS-CoV-2 RBD. The simulated structures indicated that ACE2 proteins from Bovidae and Cricetidae were able to associate with SARS-CoV-2 RBD. We found that nearly half of the key residues in turtle, snake, and bird were changed. The simulated structures showed several key contacts with SARS-CoV-2 RBD in turtle and snake ACE2 were abolished. This study demonstrated that neither snake nor turtle was the intermediate hosts for SARS-CoV-2, which further reinforced the concept that the reptiles are resistant against infection of coronavirus. This study suggested that Bovidae and Cricetidae should be included in the screening of intermediate hosts for SARS-CoV-2.     

Long-term research of stem cells in monocrotaline-induced pulmonary arterial hypertension

Our previous studies have shown that bone marrow mesenchymal stem cells (BMSCs) can inhibit the progression of pulmonary artery hypertension (PAH) in the monocrotaline (MCT) model in the short term. The aim of this study was to further investigate the long-term effect of BMSCs on PAH and to explore the mechanism of the protective effect including the pulmonary vascular remodeling and cell differentiation. PAH model was established by subcutaneous injection of 50 mg/kg MCT as previously study. Postoperatively, the animals were randomly divided into three groups (n = 10 in each group): control, PAH group, and BMSCs implantation group. Six months after injection, immunology and immunohistochemistry analysis indicated the MCT-induced intima-media thickness in muscular arteries was reduced (P < 0.05); the area of collagen fibers in lung tissue was lower (P < 0.05), and the proliferating cell nuclear antigen level in pulmonary artery smooth muscle cells was decreased (P < 0.05). Immunofluorescence showed that the cells have the ability to differentiate between von Willebrand factor and vascular endothelial growth factor. Six months after intravenous injection, BMSCs could significantly improve pulmonary function by inhibiting the ventricular remodeling and the effect of cell differentiation.     

口腔内就位道观测仪指导口腔医学生固定义齿牙备的实验研究

目的 研究口腔内就位道观测仪在口腔医学生固定义齿就位道确定中的作用。方法 选取80名经过系统牙体制备理论教育的医学生,随机分为四组(A1组：采用就位道观测仪指导制备前牙;A2组：采用常规目测法制备前牙;B1组：采用就位道观测仪指导制备后牙;B2组：采用常规目测法制备后牙),每组各20名,分别在仿真头颅模型系统上模拟21、36缺失进行固定桥基牙制备。制备后用3D扫描仪行口内模型扫描,将获取数据导入CAD软件进行倒凹及会聚度的分析和测量。凡预备体无倒凹者为合格,存在倒凹者为不合格。采用统计学软件进行合格率及基牙平均会聚度的分析。结果 A1组合格16人(合格率为80%);A2组合格9人(合格率为45%);B1组合格15人(合格率为75%);B2组合格5人(合格率40%)。数据分析表明,A1组优于A2组,两者存在差异性(P<0.05),B1组优于B2组,两者存在高度差异性(P<0.01)。桥基牙会聚度A1组优于A2组,B1组优于B2组,均存在高度差异性(P<0.001)。结论 使用口内就位道观测仪可以提高医学生固定义齿共同就位道的成功率。     

Synthesis of a 2D Cu@TiO2 composite via the design of a 1D Cu-based coordination polymer precursor for efficient and selective photodegradation of dyes

A 2D Cu@TiO₂ composite with a porous and crystalline structure was successfully synthesized via one-step and low-temperature calcination of a 1D Cu-based coordination polymer (Cu-CP), namely [Cu₂(3-dpha)(1,4-NDC)₂(H₂O)₃]_n (3-dpha = N,N′-bis(3-pyridyl)adipamide and 1,4-H₂NDC = 1,4-naphthalenedicarboxylic acid). Moreover, the Cu@TiO₂ membrane was fabricated by a simple filtration of the as-grown Cu@TiO₂ composite. Compared with the benchmark TiO₂ photocatalyst, the Cu@TiO₂ composite material with high specific surface area and reduced photogenerated electron–hole ratio exhibited good photodegradation activity and durability for gentian violet (GV), which could be attributed to the combined effect of co-doping of Cu and TiO₂ structure. Furthermore, the ˙OH and ˙O₂⁻ radicals were predicted to dominate the photocatalytic process. Therefore, this new efficient photocatalyst is a promising candidate for efficient and selective photodegradation of organic pollutants.

A 2D Cu@TiO₂ composite was synthesized via low-temperature calcination of a 1D Cu-CP. Moreover, the Cu@TiO₂ membrane was fabricated by a simple filtration of the Cu@TiO₂ composite which exhibited selective photodegradation activity for GV.     

High-frequency Noise-induced Hearing Loss Disrupts Functional Connectivity in Non-auditory Areas with Cognitive Disturbances

Dear Editor, Approximately 500 million individuals suffer from hearing loss worldwide.The number of hearing-impaired individ-uals is estimated to increase to 90...     

A rapid and highly effective approach for SARS‐CoV‐2 nucleic acid daily testing in more than four thousand single‐tube samples

BackgroundPresently, the global spread of COVID‐19 is still going on, with more than 0.6 million new cases confirmed per day (as of November 20, 2021). However, since China entered a post‐epidemic phase in mid‐March 2020, the daily number of new domestic infections in the Chinese mainland has been maintained at almost zero or single digits, which was attributed to a series of effective measures for COVID‐19 prevention and control adopted by the Chinese government. Among these measures, SARS‐CoV‐2 nucleic acid testing holds key role for the timely confirmation and isolation of the infections to prevent further transmission.MethodsReferring to the national policy requirements, since April 30, 2020, The Affiliated Hospital of Qingdao University has conducted SARS‐CoV‐2 nucleic acid testing in its PCR laboratory for patients and social workers, as well as for environmental monitoring and employee screening. As of mid‐November 2020, the daily amount of single‐tube samples for nucleic acid testing rose above 4,000.ResultsIn this article, a rapid and highly effective approach for SARS‐CoV‐2 nucleic acid daily testing is presented, allowing five technicians to complete nucleic acid testing in 6,500 single‐tube samples in one day with a high level of quality. Using this approach, since the samples entered the PCR laboratory, all testing results were reported in 2.5–3 h with satisfactory quality control and precise reporting criterion as prerequisites.ConclusionThis testing approach provides a referable workflow for other testing institutions and is expected to play an important role in COVID‐19 prevention and control.